class_docstr: Traitlet class storing a JupyterChart's params
code: def __repr__(self):
      return f"Params({self.trait_values()})"
  
imports: import json
  import anywidget
  import traitlets
  import pathlib
  from typing import Any, Set, Optional
  import altair
  from altair.utils._vegafusion_data import using_vegafusion, compile_to_vegafusion_chart_state
  from altair import TopLevelSpec
  from altair.utils.selection import IndexSelection, PointSelection, IntervalSelection
label_desc: Use image node_id 2 for calling the Params obj's underlying member method code with example usage: obj.__repr__() and returns: str, self, str